This invention relates to a support of a combined feed-out/feed-in device for a coilable tubing capable of being uncoiled and coiled up on a rotatable drum by means of the feed-out/feed-in device. Preferably, such a feed-out/feed-in device comprises two opposing feeding means defining a through-going passage for the coilable tubing through the device and exhibiting reversible feeding directions, such that the operative portions of the feeding means in pulling/pushing contact with the coilable tubing, in one feeding direction, pull the coilable tubing off the rotatable drum and, in the opposite feeding direction, push the coilable tubing in a direction towards the drum in order to coil it up thereon. The constructive shape and design of the feeding means may vary, the only requirement presupposing that the operative portions of the feeding means attack on opposite sides of the coilable tubing, developing friction therebetween, and displace themselves in a direction away from the drum or towards the same, respectively, upon uncoiling or coiling, respectively. Combined feed-out/feed-in devices are known, in which the feeding means consist of two opposing endless bands/belts, the adjacent rectilinear portions constituting said operative portions and defining the intermediate, through-going passage for the tubing. Said adjacent portions of the two endless belts rest against opposite sides of the coilable tubing and feed the same inwards or outwards in relation to the drum, dependent on the common direction of motion of said operative belt portions.
U.S. Pat. No. 5,660,235, discloses a method and a device for use in connection with operations utilizing coilable tubing, the purpose being to reduce bending and (following) straightening movements during each coiled tubing operation or running. According to this application, the coiled tubing drum and the feed-out/feed-in device are each placed on a rack part of their own, the two rack parts constituting parts of a common rack, in which the drum is placed on a rack part which is pivotally disposed about an axis parallel to the rotational axis of the drum in relation to the rack part carrying the feed-out/feed-in device, and in which the drum and the feed-out/feed-in device at any time, e.g. during the rotation of the common rack in relation to a blowout preventer installed in the operative position thereof, maintain a permanent position and orientation in relation to each other.
In per se, one may imagine that the feed-out/feed-in device was not coupled to the common support rack, but instead constituted for instance a separate unit placed on a frame, the coiled tubing drum carried by the support rack being mounted thereafter, after which the coilable tubing was uncoiled from the drum through the feed-out/feed-in device. However, the disadvantage of such an arrangement is that the end of the coilable tubing carries an end connector at which hydraulic hoses and/or current carrying cables are terminated and adapted to be coupled to a downhole tool/equipment. The end connector has a larger diameter than the coilable tubing, and the through-going passage of the feed-out/feed-in device is too narrow for letting said end connector through when the device is dimensioned for feeding a thinner coilable tubing therethrough. When said feed-out/feed-in device is mounted on a separate support frame, these restrictions imply that said end connector has to be coupled on or uncoupled, respectively, prior to each coiled tubing operation and subsequent to each finished coiled tubing operation, respectively.
If a feed-out/feed-in device has a separate frame, the rigidity of a coilable tubing will require that the feed-out/feed-in device must be spaced such in relation to the drum that a certain distance exists therebetween, in order to manually straighten out and thread the coilable tubing into and through the feed-out/feed-in device.